<template>
  <div>
    <div class="goods">
      <!-- 左侧 -->
      <div class="menu-wrapper" ref="menuWrapper">
        <ul>
          <!-- current -->
          <!-- 当li的index值===currentIndex的值时添加类名 -->
          <li class="menu-item " v-for="(good,index) in goods" :key="index" 
          :class="{current: currentIndex===index}" @click="clickItemindex(index)">
            <span class="text bottom-border-1px">
              <img class="icon" :src="good.icon"  v-if="good.icon"/>
              {{good.name}}
            </span>
          </li>
        </ul>
      </div>
            <!-- 右侧 -->
      <div class="foods-wrapper" ref="foodsWrapper">
        <ul ref="foodsul">
          <li class="food-list-hook"  v-for="(good,index) in goods" :key="index"  >
            <h1 class="title">{{good.name}}</h1>
            <ul>
              <li class="food-item bottom-border-1px" v-for="(food,index) in good.foods" :key="index" @click="showFood(food)">
                <div class="icon">
                  <img width="57" height="57" :src="food.icon"/>
                </div>
                <div class="content">
                  <h2 class="name">{{food.name}}</h2>
                  <p class="desc">{{food.description}}</p>
                  <div class="extra">
                    <span class="count">月售 {{food.sellCount}}份</span>
                    <span>好评率{{food.rating}}%</span>
                  </div>
                  <div class="price">
                    <span class="now">￥{{food.price}}</span>
                    <span class="old" v-if="food.oldPrice">￥{{food.oldPrice}}</span>
                  </div>
                  <div class="cartcontrol-wrapper">
                    <CartControl :food="food"/>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <ShopCart/>
    </div>
    <FoodFile ref="food" :food="food"/>
         
  </div>
</template>

<script>
import{mapState} from 'vuex'
import ShopCart from '../../../components/ShopCart/ShopCart.vue'
import CartControl from '../../../components/CartControl/CartControl.vue'
import FoodFile from '../../../components/FoodFile/FoodFile.vue'
import BScroll from 'better-scroll'
export default {
  data(){
    return {
      // [ 0, 754, 1068, 1542, 1664, 1882, 2119, 2433, 2939, 3633 ]
      tops:[],
      scrollY:0, //右侧值
      food:{}
    }
  },
    components:{
     CartControl,FoodFile,ShopCart
    },
    
  mounted() {
    // 通过vuex调取接口
    this.$store.dispatch("getGoods",()=>{  //dispatch调取actions==>调取mutations
       this.$nextTick(()=>{ //获取到goods列表后重新执行一次
          this._initScroll()
          this._initTop()
   })
    });
    
  },
 
  computed:{
    ...mapState(['goods']),
     currentIndex(){
      return this.tops.findIndex((top,index)=>{ //  1
        // 要满足滚动的高度要大于tops数组中的数值，同时要满足小于下一个的索引的值，将第一个满足条件的索引返回出去
        // 例如：scrollY=800,满足条件的值有754，1068，1542，找到第一个符合条件的是754 索引是1
        return this.scrollY>=top&&this.scrollY<this.tops[index+1]
      })
    }
  },
  methods:{
    // 获取商品的滚动坐标
    _initScroll(){
      new BScroll('.menu-wrapper',{
        click:true
      })
      // 创建一个BScroll插件，赋值给foodsScroll
      this.foodsScroll=new BScroll('.foods-wrapper',{
        probeType:2,
        // movable: true,
        // zoom: true
      })
      // 滚动
      this.foodsScroll.on('scroll',(p)=>{
        // console.log(p.y);
        this.scrollY=Math.abs(p.y)
      })
      // 滚动结束的地方
      this.foodsScroll.on('scrollEnd',(p)=>{
        // console.log('scrollEnd',p.y);
        this.scrollY=Math.abs(p.y)
      })
      
    },
    // 获取每个li的高度
        _initTop(){
      const tops=[] //创建空数组
      let top=0 //设置数组初始值
      tops.push(top)  //将初始值加到数组中
      // 通过refs标识获取到所有的类名是food-list-hook的li
      const lis=this.$refs.foodsul.getElementsByClassName('food-list-hook') 
      // 将获取到的li变成真数组，然后进行遍历
      Array.prototype.slice.call(lis).forEach((li) => {
        // 获取li的内容高度进行累加（li是叠加一起的）
        top+=li.clientHeight
        // 将每一次的li高度加到tops数组中
        tops.push(top)
        
      });
      this.tops=tops //将函数中的tops传递给data中的tops
      // console.log(this.tops);
    },
    // 点击菜单滚动食品
   clickItemindex(index){
    // 通过li的下标找到数组中相对应的索引及高度数字赋值给top（tops中存的是每个li的高度值）
    const top =this.tops[index]
    this.scrollY=top //将top值赋值给右侧的滚动高度
    //使用foodsScroll中的scrollTo方法将高度调成对应的（负值是因为想下滑动是负值，之前使用math.ads取了绝对值） 
    this.foodsScroll.scrollTo(0,-top,800)
   },
   showFood(food){
    this.food=food
    this.$refs.food.toggleShow()
   }
    
  }
};
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../../common/stylus/mixins.styl"
  .goods
    display: flex
    position: absolute
    top: 213px
    bottom: 46px
    width: 100%
    background: #fff;
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height: 54px
        width: 56px
        padding: 0 12px
        line-height: 14px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          background: #fff
          color: $green
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          bottom-border-1px(rgba(7, 17, 27, 0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147, 153, 159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        bottom-border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7, 17, 27)
          .desc, .extra
            line-height: 10px
            font-size: 10px
            color: rgb(147, 153, 159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240, 20, 20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147, 153, 159)
          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 12px
</style>